it's like an elephant graveyard in my hobby room

Post Reply
nama
Posts: 229
Joined: Wed Mar 30, 2011 9:44 am
Location: Japan
Contact:

it's like an elephant graveyard in my hobby room

Post by nama » Wed Aug 07, 2013 4:39 am

So i've recently been going through my collection of machines that have been sitting idle for a few months. My PET 2001, my Apple II and OSI 4P all had issues when they were working great just a few months ago. I fixed the Apple II. One of the masked ROMs was bad. it was an relatively easy fix (maybe an hour of testing) as at one point I did the finger test to see if any of the IC's were getting hot. The culprit ROM was certainly hotter than the others and it was one of the first things I changed out. One down, two to go.

I powered up my 4P last night, but I was greeted with a screen full of garbage, no reset. I had only just fixed an issue with the video on this machine, and it had been sitting idle for a few months. My temporary fix was to drop in a known working spare 505 board... I'll have to see what's wrong with the original CPU board sometime soon i guess as I hate to have non working stuff lying around. Hopefully it should be an easy fix. Fingers crossed.

The PET is still dead, it seemed to die slowly in that I was greeted by a screen of random characters, but could still make out the boot text a little, and type stuff that would appear also as random characters, but it soon died completely. Now just a screen of weirdness...not sure how to progress, may need some time to get this up and running again.

Maybe it's got something to do with the high humidity and heat here in Japan in the summer, but boy these old machines are hard to keep going. I can't imagine it'll get easier as time progresses.

P
Last edited by nama on Fri May 23, 2014 12:01 am, edited 1 time in total.

2P (1mhz 32k) - 502 + 8k + CEGMON + garbage collector fix BASIC, D&N MEM-CM9 + 24k, 540 (mono)
4PMF (2mhz 48k) - 505, 540 (color), 2 x 527, 5.25" Mini Floppy
Superboard RevD - CEGMON
Spares - 2 x 527
http://www.neoncluster.com

dave
Site Admin
Posts: 365
Joined: Tue Sep 09, 2008 5:24 am

Re: it's like an elephant graveyard in my hobby room

Post by dave » Thu Aug 08, 2013 7:29 pm

Good to hear from you!

I've got shelves full of partly working machines as well. I will have to pick one machine and get it fully working so I can get to my planned OSI projects. And then I've got a never-ending supply of projects afterwards!

Definitely let us know what happens when you start poking around the misbehaving 505 board.

Dave

Steve Gray
Posts: 158
Joined: Mon Oct 06, 2008 1:54 pm
Location: Markham, Ontario, Canada
Contact:

Re: it's like an elephant graveyard in my hobby room

Post by Steve Gray » Fri Aug 09, 2013 9:21 pm

I'm determined to get a disk system of some kind working so I can make some disk copies... badly in need of backups.

Steve
C4P+D&N floppy not working, 2x C4P not working, C1P not working, Superboard not working.
505 board, 610 board, Mittendorf board, TOSIE hacker board need testing, PicoDOS disk untested

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest